The challenge remains: A way to prevent AIDS

Scale of the epidemic leaves no time to rest

HANA EL SAHLY, M.D., BAYLOR COLLEGE OF MEDICINE

Published 6:30 am, Wednesday, December 1, 2010

Fifteen years ago I made my acquaintance with HIV/AIDS in a busy, dedicated Hartford Hospital ward where patients almost inevitably died and where doctors' compassion and abilities to diagnose and treat the afflicted were stretched beyond their limits.

Within a year, effective HIV/AIDS medications became widely used and the number of AIDS patients requiring hospitalization decreased to a point where the ward had to be reassigned to other specialties. It was a success story that is the product of too many slow painful deaths, lobbying and reassigning of priorities at private and public levels. However, it is no secret that this Connecticut hospital ward was not representative of the global AIDS epidemic trajectory.

In 2008, the number of people living with HIV/AIDS totaled 33.4 million, and the number of deaths that year was 2 million, according to World Health Organization reports. Even in the United States, the dramatic success of the HIV medications to reduce hospitalizations and mortality was not mirrored by successes in the areas of transmission reduction and HIV prevention.

The number of new infections has been relatively unchanged, with more than 50,000 new infections every year. This is the equivalent of a new diagnosis every 9.5 minutes. Evidently, the existing messages about abstinence and regular condom use are not enough to halt the transmission of the disease.

If the scientific effort to prevent HIV has not yet succeeded, it is not for lack of trying. Years of research and efforts on the part of scientists and volunteers have poured into developing methods to prevent HIV and/or reduce its transmission. The initial failures were disappointing. The latest was the STEP vaccine clinical trial, which was stopped early in 2007 because there was no benefit to participants and an apparent harm to a subgroup of participants. A pessimistic mood overtook the endeavor of HIV vaccine development and other modalities to prevent HIV transmission.

However, failures can be turned into learning opportunities. HIV researchers dissected the failures of one study and applied the lessons learned to the next. This persistence has put HIV prevention research on the rebound for the past year or so with some encouraging results. The RV144 vaccine clinical trial, also known as the "Thai trial," showed a modest effect at preventing HIV infection in results reported earlier this year. It is important to note that the Thai trial was conducted over the publicized objections of many individuals who predicted its failure.

In South Africa, using a completely different approach, researchers used a medicated, vaginally-applied gel and demonstrated significant reductions in the acquisition of HIV infections, especially in women who consistently used the gel. In another multinational study, researchers demonstrated that using an HIV medication combination daily in HIV-uninfected men who have sex with men can lower the risk of getting infected with HIV. And finally, a promising scientific breakthrough occurred in the laboratory where scientists identified specific antibodies from individuals who are infected with HIV. These antibodies were shown to be highly effective in "neutralizing" multiple strains of the virus. Until now, scientists speculated that these antibodies existed, but a thorough description of these antibodies was lacking. Other vaccine candidates are currently undergoing testing in human volunteers nationally and internationally. One of these vaccines is being tested here in Houston.

It may not offer much comfort to tell those who lost loved ones to AIDS that the community effort has achieved for AIDS in 29 years what it took 2,900 years to achieve for a disease like tuberculosis.

The scale of the epidemic does not leave much time to rest. On World AIDS Day 2010, we ought to remember those who died of AIDS with renewed commitment to action to alleviate and contain this epidemic, and extend the lessons learned from AIDS thus far to other, equally grave, epidemics.